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7x57 Ack Imp for F Class?

Am replacing my shotout 6AI barrel with a 6mm Super LR barrel for short and mid range F Class next Summer.

Leaves me with a whack of 6AI brass that I was thinking of necking up to 6.5x57AI for a long range rifle. But seeing the success of various 7mm cartridges in F Class this Summer, I am seriously thinking of necking up the 6AI brass to 7x57AI.

Have annealed some 6AI cases and using a Redding tapered .22 to 7mm expander, doesn`t seem to be a problem. And Redding makes 7x57AI reloading dies as a regular item.

Just got Kiff print # 20639 from PT&G for the 7x57AI reamer, designed by Kelly Miller. Great service from those folks in Oregon, as usual.

There is a custom bullet maker here in Canada producing a 168 gr 7mm VLD bullet with a BC of .71. Hard to believe but an F Class buddy using this bullet in another wildcat says the drop at 1000 yds confirms the BC.

So my question is, has any forum member used the 7x57AI in competition and what is the opinion of same? Is getting 2800 fps with a 168 gr bullet a realistic expectation?
 
I have been looking at that round for a nice midrange F-Class rifle. I see no reason why it wont reach the 2800 fps mark very easy! What is the brand name of the 168 bullets you are talking about?
 
I've been shooting f-class for 5 years with a 7x57 wildcat version, but it's not an ackley. I use 30-06 cases, run them through the wildcat die, cut them 6mm shorter, and fireform. The final product is very close to an ackley 7x57, 40 deg shoulder, .315 neck length. Shooting the 168 Berger 2880 to 2920, 50.5 grain S365 (your H4350).

The carttridge (called a 7mm Tombe), is 99% an Ackley 7x57. Extremely accurate, easily holds it's own against the straight .284 Winchester, better barrel life than the .284, brilliant for F-class.

You will not be sorry!
 
Thanks for the replies, guys. Just got back from the 10 day Canadian Fullbore Championships. Had to shoot in F/TR with my backup .308 Savage VLP. My good buddies are spreading rumours that I got sliced and diced at the long ranges with my "puny" 26 inch barrel but, hey, that`s what friends are for.

Sure did miss the velocity of the 6AI but that velocity gave me a one season barrel.

DSBW, great info. Always nice to hear from outside North America. Sounds like you have a beauty cartridge there. Your experience gives me further resolve to go with the 7x57 Ackley.

bsoutlaw32, the name of the bullet manufacturer is Matrix Ballistics. He is in the province of British Columbia, Canada. I don`t know the in and outs of shipping bullets across the border. He responds quickly to e-mail questions. Check out his web site at
http://www.matrixballistics.com/index.html
 
dsbw said:
...
The carttridge (called a 7mm Tombe), is 99% an Ackley 7x57. Extremely accurate, easily holds it's own against the straight .284 Winchester, better barrel life than the .284, brilliant for F-class.
Is this the cartridge that the South Africans won the F-Class World Championship some years ago and started people wondering whether 7mm was a new contender?
 
I have thought long and hard about this cartridge and I think the capacity would make for a great 7mm cartridge. The thing that has kept me from doing it is the inability to get Lapua brass to fireform. This season I went with a 6.5 x 55 AI that I have been happy with, even the fireforming loads were extremely accurate.

wade
 
Anyone ever try a 7X55AI?? It is easy to expand the necks on 6.5X284 Lapua brass to 7mm so that part shouldn't be a problem. If you keep the neck shoulder junction at the same place, the fireforming loads would probably shoot very well one node down. That's how it works with the 284 Shehane.
 
There is a custom bullet maker here in Canada producing a 168 gr 7mm VLD bullet with a BC of .71. Hard to believe but an F Class buddy using this bullet in another wildcat says the drop at 1000 yds confirms the BC. [1000yardstare]

Bryan Litz lists Matrix 7mm bullets in the expanded second edition of Applied Ballistics for Long Range Shooting's data section. The 168gn merits G7/G1 BCs of 0.316 and 0.617, very close to the 168gn Berger VLD as one would expect. The 190gn VLD is 0.344/0.673, BCs again close to similar shape bullets from others.

So...ooo, they're well designed bullets, but sadly don't reinvent the laws of physics and aerodynamics. No doubt the G1 BC of .71 is somewhere around correct for one particular velocity and that one velocity only, so nobody is lying!
 
As it turns out I went with the 6.5x57AI. Brass originally old 6AI necked up but more consistent results with new 7x57 necked down. Use the COW fireforming method - 17 gr Red Dot, fill with COW, dab of grease.

Main reason for the 6.5 is a good supply of 142 SMK and 139 Scenar at reasonable prices. For some reason 7mm competition bullets in any quantity are a tough buy in Canada, either going the custom route or chasing import/export permits.

Had a 600/1000 F Class practise yesterday. Squadded with the 2010 Ontario F Class Champion. He just got a new barrel for his winning 7mm/.270 WSM and is sticking with 180 Bergers.

With a 7mm/.270 WSM winning the Ontarios and a .284 Shehane winning the Canadians last year it will be interesting to see how many new 7mms are on the firing lines this Summer. I will keep my eye peeled for a 7AI.

Bill
 
Bill,

we had one or two people shooting 7X57AI in long-range benchrest here for a while with reasonable results. Nobody in F Class that I've heard of so far. While we get US made bullets (at a price!) with only the occasional supply hiccup, 7X57 brass is more of an issue. We can get RWS cases but they're special order and VERY pricey. Mind you, with the amounts some of our 'Open' guys are spending, a couple of hundred RWS cases is possibly a minor investment and we have had people buying 8X68 RWS brass to form the 7mm Boo-Boo.

Our Open shooters have as you know definitely discovered 7mm, but in .284W, .284 Shehane, 7mm SAUM and variants on the WSM theme only. The movements this season are to the .284 (downgrading from WSM for barrel life); and to the SAUM (for efficiency and barrel life). As mentioned, we had a few Boo-Boo shooters in the early days, so the trend is definitely to smaller capacity cases over time - so who knows?

I'm probably going to give .280 Rem AI a go at some time or other using Lapua .30-06 brass and also able to sidestep the need for a magnum bolt for the SAUM / WSMs, but I always have been a maverick on the GB F Class scene!

Laurie
 
I've got a dumb question.

Where does the plain 7X57 case stand in this discussion? Any one have experience with it using the better 168gr size bullets? And what kind of velocity?
Privi Partizan supplies a case at a good price for the 7X57.
 
Normmatzen........good question.

I would place the 7x57 in the same class as the 7mm-08. Five years ago the 7-08 was a popular F Class cartridge in Canada on the old one minute V-ring. But then the 1/2 minute V-ring/X-ring raised its ugly head on the International ICFRA and U.S. NRA targets.

The rigs are so good today that you have to have a fairly high percentage of Vs/Xs to make the winner`s circle. F Class shooters are relying on sheer horsepower to fight the wind and stay within that 5 inch circle at 1000 yds.

The 7x57/7-08 don`t have enough oomph to stave off wind switches at long range. There are those that would argue that if you are reading the wind properly the cartridge shouldn`t matter. But I suspect those are the same shooters who 4 years ago swore by the 6BR for 1000 yds. Haven`t seen a 6BR at 800/900/1000 in 2 years.

I would say the 7x57 could be a good cartridge out to 600 yds on the 1/2 minute F Class target. Haven`t tried it myself.

Bill
 
Bill,

Thanks for the excellant reply. I perked up my ears over this thread as I am building a large ring 7X57 sporter for hunting in California and that caliber got my attention. I really haven't read about the difference between the 7X57 and 7X57 Ackley.

Here in California I and my 243 WIN bench rest gun get beat regularly at 1000 yd by 6mmBR and 6mm Dasher. A lot of other old guys like myself are very effective with the 6mmBR, so maybe there is hope for the 7X57?
 

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